Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H4/00—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques
  • D01H4/02—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques imparting twist by a fluid, e.g. air vortex
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H1/00—Spinning or twisting machines in which the product is wound-up continuously
  • D01H1/11—Spinning by false-twisting
  • D01H1/115—Spinning by false-twisting using pneumatic means
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H5/00—Drafting machines or arrangements ; Threading of roving into drafting machine
  • D01H5/18—Drafting machines or arrangements without fallers or like pinned bars
  • D01H5/60—Arrangements maintaining drafting elements free of fibre accumulations
  • D01H5/66—Suction devices exclusively

Definitions

• the invention relates to a device for producing a spun thread from a staple fiber structure, with a drafting unit having a pair of delivery rollers, with an air nozzle unit arranged downstream of the drafting system, which contains a swirl chamber with an exhaust air duct, and with at least one cleaning duct assigned to the pair of delivery rollers with a suction opening.
• a device of this type is known from EP 1 207225 A2.
• a staple fiber dressing is drawn into a fiber ribbon in the drafting system, which is then given the spinning rotation in the air nozzle unit.
• the sliver is first passed through an inlet duct of the air nozzle unit into a swirl chamber, which is assigned a fluid device for generating a swirl flow around an inlet opening of a thread take-off duct.
• the front ends of the fibers held in the sliver are guided into the thread take-off channel, while the rear free fiber ends are spread apart, caught by the vortex flow, and are rotated around the front ends that are already in the inlet opening of the thread take-off channel, that is to say, integrated, resulting in a thread with largely real rotation is generated.
• Such a device allows high spinning speeds, which places high demands on the drafting system arranged upstream of the air nozzle unit.
• the particularly fast-running delivery roller pair tends to cause fiber fly to settle on its peripheral surfaces.
• the delivery roller pair of the known device is assigned a suction opening of a cleaning channel, which is intended to keep the delivery roller pair clean.
• the cited document leaves open which vacuum source the cleaning channel is connected to, but it can be seen from the patent figures that obviously different vacuum sources are provided for the exhaust air duct and the cleaning duct.
• the present invention is based on the object of providing a particularly simple construction for a device of the type mentioned above and, moreover, of intensifying the cleaning process if necessary.
• the object is achieved in that the cleaning duct is connected to the exhaust air duct with an opening and in that in the region of the opening a compressed air opening of an injection duct which reinforces the underpressure of the exhaust air duct is provided.
• a common fan can be used for the exhaust air from the swirl chamber and for cleaning the pair of delivery rollers, which leads to a significantly reduced production outlay compared to the prior art.
• a compressed air opening of an injection channel which reinforces the negative pressure of the exhaust air channel is provided in the area of the mouth, the negative pressure for intensifying the cleaning process can be temporarily increased and even almost doubled. This is possible without increasing the performance of the fan.
• the injection channel can fully act back to the suction opening, since it opens with its compressed air opening at a particularly suitable point.
• the suction for periodic cleaning can be increased if necessary by periodically switching on the injection channel, in particular in the event of an interruption in operation in connection with a preparation process.
• the reinforcing effect is particularly high when the cleaning channel runs in a straight line between its suction opening and its mouth and is preferably a maximum of 20 mm long.
• the air nozzle unit can be pivoted together with the cleaning channel relative to the pair of delivery rollers in such a way that the suction opening can be moved to the area of the wedge gap formed by the pair of delivery rollers.
• the device shown in FIG. 1 is used to produce a spun thread 1 from a staple fiber dressing 2.
• the essential components include a drafting device 3 and an air nozzle unit 4.
• the staple fiber structure 2 to be spun is fed to the drafting device 3 in the direction of delivery A and drawn off as spun thread 1 in the direction of take-off B and passed on to a winding device (not shown).
• the drafting system 3, which is only partially shown, is preferably designed as a three-cylinder drafting system and contains a total of three pairs of rollers, each of which contains a driven lower roller and an upper roller designed as a pressure roller. The first two roller pairs, not shown, are followed by a delivery roller pair 5, 6, of which the delivery roller 5 is a driven lower roller and the delivery roller 6 is a pressure roller.
• the staple fiber structure 2 is warped to the desired fineness in a known manner.
• the air nozzle unit 4 following the drafting unit 3 at a short distance and giving the spinning rotation can in principle correspond to the device described in the publication mentioned at the beginning.
• the fiber bundle 7 is fed to the air nozzle unit 4 via an inlet duct 8. There follows a so-called swirl chamber 9, in which the sliver 7 is given the spinning twist, so that the spun thread 1 is formed, which is drawn off through a thread take-off channel 10.
• a fluid device generates a vortex flow in the vortex chamber 9 by blowing compressed air through tangential air nozzles 11 opening tangentially into the vortex chamber 9.
• the from the Compressed air emerging from nozzle openings is discharged through an exhaust air duct 12, which initially has an annular cross section around a spindle-shaped stationary component 13, which contains the thread take-off duct 10, and then merges into a larger suction duct 14 with the suction direction C.
• an edge of a fiber guide surface 15 is arranged as a swirl lock, which runs slightly eccentrically to the thread take-off channel 10 in the area of its inlet opening.
• the fibers to be spun are held on the one hand in fiber strips 7 and thus guided from the inlet channel 8 into the thread take-off channel 10 essentially without imparting rotation.
• the fibers in the area between the inlet channel 8 and the thread take-off channel 10 are exposed to the effect of the vortex flow, by means of which they or at least their end regions are driven radially away from the inlet opening of the thread take-off channel 10.
• the threads 1 produced with the described method thereby show a core of fibers or fiber regions running essentially in the longitudinal direction of the thread without substantial rotation and an outer region in which the fibers or fiber regions are rotated around the core.
• this thread structure comes about because leading ends of fibers, in particular those whose trailing areas are still kept upstream in the inlet channel 8, essentially reach the thread draw-off channel 10 directly, but trailing fiber areas, especially if they are in the entrance area of the inlet channel 8 can no longer be held, pulled out of the sliver 7 by the formation of eddies and then rotated around the thread 1 formed.
• fibers are integrated at the same time both in the thread 1 being formed, as a result of which they are drawn through the thread take-off channel 10, and are also exposed to the eddy current, which accelerates them centrifugally, that is, away from the inlet opening of the thread take-off channel 10 and draws them into the exhaust air channel 12.
• the fiber areas drawn by the vortex flow from the fiber ribbon 7 form a fiber vortex opening into the inlet opening of the thread take-off channel 10, the so-called sun, the longer portions of which wind spirally around the outside of the spindle-shaped input area of the thread take-off channel 10 and in this spiral against the force of the flow in Exhaust air duct 12 are drawn against the inlet opening of the thread take-off duct 10.
• a device of this type allows particularly high spinning speeds, which can be in the order of 600 meters per minute. It is obvious that very high demands are placed on the drafting system 3 because the delivery roller pair 5,6 has to run particularly quickly due to the high warping power required. This inevitably leads to the delivery roller pair 5,6 being exposed to a high level of flying through loss fibers. For this reason, the bottom roller of the pair of delivery rollers 5, 6 is assigned a suction opening 16 of a cleaning channel 17 and the pressure roller 6 is assigned a second suction opening 18 of a further cleaning channel 19.
• both cleaning ducts 17 and 19 open out in the interior of the air nozzle unit 4 into the exhaust air duct 12 or, in its continuation, the suction duct 14.
• the cleaning channel 17 assigned to the lower roller 5 runs in a straight line and is slightly tangential to the lower roller 5 and is preferably no longer than 20 mm.
• the cleaning duct 17 is now connected to the exhaust air duct 12, 14 with an orifice 20, a compressed air opening 22 of an injection duct 21 which increases the negative pressure of the exhaust air duct 12, 14 if required being provided in the region of the orifice 20.
• the effect in the exhaust air duct 12 can be temporarily significantly increased, for example in order to temporarily clean the surfaces of the delivery rollers 5, 6 in the event of an interruption in operation.
• the injection channel 21 is only switched on periodically and in particular only during an interruption in operation. Because the compressed air opening 22 of the injection channel 21 is located in the region of the mouth 20 of the one cleaning channel 17, the effect is particularly great for this cleaning channel 17.
• the air nozzle unit 4 can be pivoted somewhat in the event of an interruption in operation, so that the suction opening 16 of the cleaning channel 17 is then directed directly against the wedge gap 24 of the delivery roller pair 5, 6.
• the pivot axis 23 for the air nozzle unit 4 is arranged correspondingly geometrically.
• a cleaning channel 17 that is as straight and short as possible reinforces the effect.
• an inhomogeneous fiber stream supplied again from the drafting system 3 can first be deflected directly into the suction system via the cleaning channel 17 during a piecing process.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Spinning Or Twisting Of Yarns (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34638674

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (5)

Citations (5)

Family Cites Families (7)

• 2003
  • 2003-12-11 DE DE10358484A patent/DE10358484A1/de not_active Withdrawn
• 2004
  • 2004-10-15 US US10/582,358 patent/US7328569B2/en not_active Expired - Fee Related
  • 2004-10-15 CN CNA2004800366328A patent/CN1898423A/zh active Pending
  • 2004-10-15 WO PCT/EP2004/011589 patent/WO2005061765A1/de active Application Filing

Patent Citations (5)

Non-Patent Citations (1)

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